1. Field of the Invention
The present invention relates to the diagnosis of cancer, and particularly to lung cancer detection by optical analysis of body fluids that uses fluorescence spectroscopy to examine samples of blood, urine, and/or sputum to diagnose cancer of the lungs during pre-malignant, early malignant, and advanced malignancy stages.
2. Description of the Related Art
Cancer is often a fatal disease. Modern medicine has developed many modes of treating cancer, including surgical removal of tumors, chemotherapy, immunological therapy, etc. However, the key to effective treatment is early detection.
A number of diagnostic tests are available for determining the presence of cancer. These tests include: surgical biopsy; prostate specific antigen (PSA); DRE tests; computed axial tomography (CAT or CT scans); magnetic resonance imaging (MRI) scans; ultrasound scans; bone scans; positron emission tomography (PET) scans; bone marrow testing; barium swallow tests; endoscopy; cytoscopy; T/Tn antigen tests; mammography; and other tests. Although effective to a greater or lesser extent, each of these tests has advantages and disadvantages.
Some tests, such as PSA, pap smears, and mammography, are specific to particular organs. Others, such as biopsy, endoscopy, bone marrow, and cytoscopy, are invasive tests that often result in considerable discomfort to the patient. Still others, such as CAT scans and MRI scans, are quite expensive and require complex instrumentation.
In particular, cancer of the lung has a very low survival rate (less than 20%) and represents the highest incidence of cancer in most developed countries. Active and passive smoking, along with polluted ambient air, are the main causes of lung cancer. Most of the methods of cancer detection, particularly ultrasound or CAT scans and bronchoscopy, are incapable of early detection. Many scientists and physicians have tried sputum cytology and CT scans coupled with bronchoscopy for early detection, as well as biochemical approaches to identifying and quantifying some lung cancer biomarkers from blood serum. In this approach the sensitivity is less than 70%. Therefore, greater sensitivity is needed to make these techniques viable.
Thus, there is a need for a simple, relatively inexpensive, noninvasive method of screening patients for the presence of cancer, and particularly cancer of the lung, that can be used both for preliminary diagnosis or mass screening of patients, and also during treatment to determine whether cancer has gone into remission. Thus, lung cancer detection by optical analysis of body fluids solving the aforementioned problems is desired.